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How Indexes work?
- To: openldap-technical@openldap.org
- Subject: How Indexes work?
- From: Steeg Carson <steeg.carson@googlemail.com>
- Date: Wed, 15 Dec 2010 12:45:31 +0100
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Hello,
I try to understand, how the LDAP-Indexes work.
If I configure a Index for a Attribute like:
index myAttribute eq
the index file myAttribute.bdb is build in the data directory.
When I search then
ldapsearch -x -h localhost -D".." -b"<baseDN>" "(myAttribute=<searched key>)"
how will the LDAP-Server process this request?
Is there anywhere a good documentation?
My assumption is:
* At first, a the Index is looked up. The result are only the matched IDs.
* The LDAP-Server now can quick give back all entires form id2enty.bdb
If I use Indexes, are all other entires are examined too after give back the result from indexes?
I have a database, and my search is like shown above. The search takes long. The cache is configured, the size is enough
(approx. dn2id.bdb + id2entry.bdb).
But what I see, is that the write IO from LDAP is enormously (seen with iotop). During the whole search, the write IO is higher than the read IO.
Why?
Thanks for help.
Steeg